Can we have an glossary of initials people use? It would be very useful to people new to Linux

I've been trying to get to grips with Ubuntu for a month or two. It's very good, but looking in help pages for answers to the questions I have people very often use initials which are totally new to me.
You might have it already (if so, apologies - I haven't found it!), but could a page be posted containing all the initials which people use in their posts, and the meanings of them?